Loom stop motion



y 10, 1955 K. E. SANDERSON 2,707,977

LOOM STOP MOTION Filed Feb. 11, 1955 2 Sheets-Sheet 1 19 79/17 I/QI'OLINE 15 zIg z AC. 12 V UNGROUNDED.

@ 5 9 KENNETH i ifi g ow A TTORNEY y 19, 1955 K. E. SANDERSON 7,977

LOOM STOP MOTION 2 Sheets-Sheet 2 Filed Feb. 11, 1955 k KQZ%M% A TTORNEYUnited States Patent 0 LOOM STOP MOTIDN Kenneth E. Sanderson, Hopedale,Mass., assignor to Draper Corporation, Hopedale, Mass., a corporation ofMaine Application February 11, 1953, Serial No. 336,280

10 Claims. (Cl. 139-336) This invention pertains to a stop motion forlooms, and more particularly, to an electro-mechanical type stop motioneffective upon failure of power to the loom and upon failure of aweaving thread therein.

It is a general object of the invention to devise a stop motion for thepurposes stated which shall be simple, effective and certain in itsoperation.

It is a more specific object of the invention to devise a simple stopmotion circuit which shall act as a power failure loom knock-off meansand which shall function with a closed circuit at low voltage and withlow current consumption.

It is a further object to devise a stop motion circuit in which sparkingat the drop wires shall be greatly reduced and further, which shall havea slow or delayed action such that reasonable swaying of the wires willnot result in stopping the loom.

It is a further object of the invention to devise a stop motion circuitin which the resistance through which current to the various branches ofthe circuit is fed also serves as an indicator.

' A further obiect is that of devising a stop motion which, once havinggiven a definite signal for stopping the loom, cannot be aflected bybouncing of the stop motion drop wires so that the signal would be atleast temporarily nullified.

Other objects of the invention will become apparent from the followingmore detailed disclosure.

In the operation of looms for weaving stop motions are provided forsignalling a knock-off of the loom upon failure of a weaving thread,either filling or a warp thread. It has further been desired andsuggested (U. S. Patent 2,300,098) that provision be made for knocking01f the loom upon failure of power thereto. While the loom would, ofcourse, stop if power to it failed, it is desired that the knock-offmeans function so that when power returns, the loom may not start underimproper conditions.'

It is desired that these stopping means be combined in a simple,effective circuit. Electric stop motions are also beset by certainobjectionable characteristics, notably a tendency to sparking at thedrop wires as they complete their circuit and then temporarily losecontact with their electrodes. The vibration of a loom is considerableand causes a swaying and bouncing of the drop wires so that in someinstances false indication or signal is given thereby stopping the loomeven though no real reason for the stop is present. Again, when a signalhas been properly given, the bouncing of the wires may negative it for abrief interval causing the stop motion to make another try beforeknock-off is effected.

According to the invention these and other diificulties are overcome byuse of a circuit which is primarily resistive in nature rather thaninductive. The various parts of the circuit incidental to stopping upondefinite cause are branched to receive current selectively through aresistance of low value and having a substantial thermal lag. Normallycurrent flows through said resistance 2,707,977 Patented May 10, 1955"ice and through a closed circuit in that branch effective for stoppingupon power failure to energize an electro-magnet for retaining a detentor the like out of the path of a moving actuator. The resistance is ofsuch low value as to pass current required to energize the magnet andwhen a circuit is completed through the other branch in which a stopmotion thread condition detector is maintained, the resistance passesthe current which is diverted from the first branch, but since the totalresistance is less, heats the feed line resistance which has asubstantial thermal lag, thereby causing a delay in the functioning ofthe circuit as it signals a knock-off to stop the loom. If anincandescent lamp of suitable characteristics is used as a resistance,it may also serve as a visual signal. Such a lamp must have very lowresistance when cold and thus serves to pass the small current needed toenergize the holding magnet; however, it does not glow without morecurrent. When the current is grounded or the circuit otherwise completedat the stop motion detector, the current tends to rise rapidly, but isheld down momentarily as the resistance of the lamp filament increasesrapidly upon becoming heated. The action of the circuit is thus renderedsufiiciently sluggish so that the swaying or other unintended contactsmade by drop wires has no apparent effect.

When current is passed through the stop motion branch of the circuit,the voltage drops at the electromagnet until it can no longer hold thedetent. The latter then moves to position to be picked up by the movingactuator whereupon the loom will be knocked off.

The invention will be described in greater detail by reference to theaccompanying figures of drawing, wherem:

Fig. l is an end elevation of a loom to which the in vention has beenapplied.

Fig. 2 is an electrical diagram showing in simple manner the circuitinvolved.

Fig. 3 is a vertical section through the moving actuator and detentportion of the mechanism.

Fig. 4 is an elevational view of part of the device shown in Fig. 3.

Fig. 5 is a View, partly in section, showing the detent resetting means.

Now referring to Fig. 1, part of a loom such as that described in fullin U. S. Patent 2,604,123 has been illustrated and including a loomside10, beam bearing 11, driving motor 12, side brackets 13 and 14 andfilling inserting means supporting and actuating devices and enclosingcasings generally indicated by numeral 15.

The motor 12 is controlled to be stopped and started by lever 16connected through linkage to a hand lever 17 pivoted at 18 and having aknob 19 by which it is gripped. This lever has a second arm at 20 whichis connected at one end 21 of link 22 connected at its other end to hellcrank lever 23. This latter lever is pivoted on a fixed stud 24 and itsother arm is connected to a second link 25. Link 25, in turn, attachesto a second bell crank 26 the motion of which is conveyed to lever 16through cross link 27. Movement of the starter lever 17 to the full lineposition, Fig. 1, sets the loom in motion assuming the power has beenturned on for motor 12. Preferably that motor is of the type having aninternally carried clutch and brake and the latter is controlledsimultaneously with the former. Movement of the linkage to the dottedline position disengages the clutch and applies the brake, thatoperation being re ferred to as knocking off the loom.

A moving actuator may be employed as a part of any convenient cyclicallycontrolled element on the loom and here is in the form of a projectionor tooth 2'8 attached to disk members 29 on cam shaft 30. These carry aneccentric pin 31 which causes pitrnan 32 to actuate the fillinginserters in a manner disclosed in the patent above identified.

Now referring to Figs. 3 and 4 as well as Fig. 1, disk members 29include a central hub 33 keyed by key 34 to shaft 3%), an inner, dishedplate 35 in a notch in which tooth 28 is held and a ring 36. These threemembers are bolted together by bolts 37 and the eccentric pin 31. Shaft36 is borne in hearings in the loomsides, one such being illustrated at38.

A detent SS is pivoted at 4% in the forked end of a depending arm 41angularly bent at its upper end to continue in a horizontally disposedextension 42 pivoted at ,43. The latter is a part of a boss cast orotherwise formed as a part of casing 44 attached to loomside It). Aspring 45 between a cupped projection 46 and the top surface of thecasing normally maintains the arm 41 as in Fig. 4. A coil spring 47,Figs. 3 and 5, engages a collar 48 on pivot 40 and also the forked endof arm 41, and is under tension so that the detent 39 drops to theposition of Fig. 4 except at such times as it is held in elevatedposition by electro-rnagnet. The detent is fixed on its pivot 46 to movewith it.

Downward movement of the detent is stopped by screw 49 threaded througha transverse member 50 in arm 41.

The collar 48 has a pin 51 passing through it and the pivot 46 and inaddition to holding the collar in place, the pin extends downwardly tobe engaged at times tfy a spring clip 52 carried by a bracket 53 clampedto rod 25 by a set screw or by any other satisfactory means.

This bracket is in the form of a pair of spaced, parallel cylindersconnected by a web and, as shown, one said cylinder serves as a means tomount it on the rod 25 while the other is bored to receive a plunger 54which is spring pressed to a position in which it projects slightly fromthe bracket. Spring 55 may be compressed to relieve shock and to permitoperation with less accurate adjustment of parts.

An electro-magnet 56 having a core 57 and windings 58 is fixed in casing44 so that the end of the core is positioned to align with the free endof detent 39. An air gap is maintained by a brass plate 59 of .005.0l0"in thickness or by any other suitable means. The magnet is a part of acircuit later to be described, but sufiice it to say at this point thatthe circuit is closed and the magnet is essentially a holding magnet andwill not pick up the detent once it has been released. It is for thatpurpose that clip 52 having a V-shaped end 60 is used. When the loom isknocked off, the clip moves to the left, Figs. 4 and 5, and gets on theside of pin 51 so that when the loom is started again, the pin will bepushed l to the right and will swing the detent from the position ofFig. 4 to one where the magnet will hold it out of the path of themoving actuator.

One circuit that may be utilized is shown in Fig. 2.

The circuit is essentially a direct current one; although it may beoperated on alternating current, that is more difiicult and not assatisfactory. Since alternating current is used for the motor 12, thesame source of power is availed of for the stop motion circuit and thussome form of rectification is required. Preferably, a full waverectifier 61 of selenium type is fed from the 12 v. line and while theoutput at one side of the rectifier is grounded as at 62, the other isconnected by feed line 63 to' binder post 64 to which are also connectedtwo branch circuits.

The first of these branches 65 leads to coil 58 and ground 66.

The second 67 leads to one of the electrodes of a stop motion detector68 the other electrode of which is grounded at 6?. These electrodes aresupplemented by a series of so-called drop wires, not shown, since thesame and the action of this type of electrically actuated stop motiondetector are well known see U. S. Patent No. 2,200,148. Of course, uponrelease of a drop wire upon failure of a weaving thread, the detectorcircuit is grounded.

A resistance R of special characteristics is placed in series in feedline 63 so that current to either branch must pass through it. Thisresistance preferably takes the form of an incandescent lamp such as a12-16 v. truck type headlight bulb. The life of these lamps is farbeyond anything to which they may be subjected and their resistance isrelatively low when their filament is cold. When caused to glow theresistance increases very rapidly and the present circuit takesadvantage of these resistance characteristics. Normally a very smallcurrent in the order of about /2 amp. at 9 v. is sufficient to energizemagnet coil 58 and hold the detent. That current passes lamp orresistance R without heating its filament appreciably.

When a thread fails and circuit through the stop motion detector iscompleted, current tends to be shorted to ground at that side and todecrease at the magnet side Here the resistance of the magnet coil isconsiderably greater in value than the resistance of the detectorcircuit. As a result the magnet ceases to hold and the detent drops intothe pathway of the moving actuator. As the latter catches the detent 39it swings it and arm 41 against spring 45 so the back of the detent orsome other correspondingly moving part engages plunger 54 and pushes itand rod 25 to the left, Figs. 1 and 4, thus knocking off the loom.

It is at the thread failure stopping phase that the hot resistancecharacteristics of resistance R come into play. Since its resistanceincreases greatly as the filament begins to glow, there is a lag ordelay in the completing of the detector circuit and also in deenergizingthe coil 58. This can by'the selection of proper parameters within thecircuit be fairly widely varied, but it is sufficient for all practicalpurposes if the lag is of a duration such that swaying of the drop wiresand other unintended contacts which might complete the detector circuitare prevented from so doing. However, it is a fact that when oncereleased, the detent may not be recovered by the magnet and thus asignal to stop, once completed, cannot be recalled as has beenexperienced heretofore when a released drop wire has temporarily beenbounced from its electrodes or one of them.

Sparking at the drop wires is reduced first, since the normal 12 v. 3500milliamp current at the detector is reduced to 9 v. at 850 milliamps.Further, the circuit is purely resistive instead of inductive andtherefore the tendency and magnitude of sparking are greatly lessened.

While not so shown here, the lamp may be used as a visual signal sinceit becomes lighted only when the stop motion and loom knock-off havestopped the loom.

In the case of a power failure, current merely ceases to flow and thecoil 58, failing to be energized, releases detent 39. The loom will thencoast until the moving actuator catches detent 39 to perform theirintended function. Thereafter, power may be returned to the circuit, butthe loom must be started manually.

Reverting to Fig. 1, current is brought in to a starter box 70 ofconventional type and then is fed to motor 12 by conductor 71, and torectifier 61 through conductor 72. The rectifier and lamp or resistanceare here housed in a box 73 from which branch feed lines 65 and 67 maybe seen leading to magnet 56 and to the stop motion detector which isspecifically a warp thread detector, but which, of course, might wellfunction upon failure of a filling or any Weaving thread.

In fact, while only a single stop motion detector is herein shown as itis desired to simplify the showing two or more detector systems maybecome a part of the circuit. Of course, if the lamp is to become asignal as well, it must be placed in an appropriate position, e. g., onthe arch or some more elevated, open part of the loom.

To review the operation briefly, assume the loom to be running and thatpower fails. The loom will, of course, start to coast to a stop and thedeenergization of magnet 56 releases detent 39. The detent immediatelydrops and the loom continues to coast until tooth 28 picks up the detentand swings it and arm 41 so that through plunger 54 and link 25, theknock-off means is actuated.

If the failure of a weaving thread occurs, current normally flowingthrough resistance R which is not heated by the small current requiredfor the coil 58 is shorted to ground through the stop motion detector68. Rise in current value due to drop in resistance at branch 67 ascompared to that in branch 65 starts to heat the resistance R whichresponds with added resistance so that a lag in deenergizing magnet 56prevents unintended stopping. However, if actual thread failure ispresent the magnet does release the detent and stopping then occurs asbefore.

To start the loom, shipper lever 17 is moved manually to the full lineposition and the m will start if all faults have been remedied. The clipend 60 pushes on pin 51 and swings the detent to a position to be heldby the magnet. Link moves farther in each direction than pin 51 so theclip is of spring material and V-shaped end 60 snaps by pin 51 at eachmovement of the link. If the loom is stopped manually the detent istripped, but, of course, will be reset when the loom is started. Ifpower has failed, movement of the shipper lever cannot reset the detentas the magnet is not energized. Likewise if a drop wire is down or otherthread fault still evident, attempted resetting is immediatelyaccompanied by stopping through the mechanism herein described as thedetent cannot be held by the magnet so long as the circuit is throughthe detector rather than the magnet.

While it is conceivable that more than one projection 28 may be used asa moving actuator, that would make it inevitable that the loom wouldthen stop at more than one position. Since it is desirable to stop aloom with the harnesses level and the filling inserting means out of theshed, it is preferred to use only one such element and thus to assurestopping at one definite position only. This does mean that if only onetooth 28 is employed, the loom must be one having a capability ofcoasting a full revolution at power failure.

By way of example, the incandescent lamp preferably used as a resistancein the feed line has a resistance of 1.2 ohms at 9 v. While a drivingmotor with integral clutch and brake is shown by way of illustration,that may be supplanted by the older type of drive wherein a motor drivesto an external clutch and where an independent brake is used.

While one embodiment of the invention has been disclosed, it is to beunderstood that the inventive concept may be carried out in a number ofways. This invention is, therefore, not to be limited to the precisedetails described, but is intended to embrace all variations andmodifications thereof falling within the spirit of the invention and thescope of the claims.

I claim:

1. In a loom the combination of an electrically operated power means, aknock-ofif system for said power means, a moving actuator and a detentmovable to and from a position to be engaged by said moving actuator,and when so engaged, being further movable for causing said knock-offmeans to stop the loom, a circuit having two branches and a current feedline to said branches, a holding magnet for said detent in one branchand a stop motion detecting means in the other branch, and a resistancehaving a thermal lag in said current feed line.

2. In a loom the combination of an electrically operated power means, aknock-off system for said power means, a moving actuator and a detentmovable to and from a position to be engaged by said moving actuator,and when so engaged, being further movable for causing said knock-offmeans to stop the loom, a circuit having two branches and a current feedline to said branches, an electro-magnet in one said branch forretaining said detent out of contact with said moving actuator, a stopmotion detecting means in the other said branch effective upon failureof a weaving thread to initiate stopping of the loom, and means in saidfeed line for passing current to said electro-magnet and for reducingsparking and slowing the action of the stop motion detecting means whichcomprises a relatively low resistance having a substantial thermal lag.

3. In a loom the combination of an electrically operated power means, aknock-off system for said power means, a moving actuator and a detentmovable to and from a position to be engaged by said moving actuator,and when so engaged, being further movable for causing said knock-01fmeans to stop the loom, a circuit having two branches and a current feedline to said branches, an electro-magnet in one said branch forretaining said detent out of contact with said moving actuator, a stopmotion detecting means in the other said branch effective upon failureof a weaving thread to initiate stopping of the loom, and means in saidfeed line for passing current to said electro-magnet and for reducingsparking and slowing the action of the stop motion detecting means whichcomprises an incandescent lamp having a low resistance when its filamentis relatively cool and a relatively high thermal lag.

4. In a loom the combination of an electrically operated power means, aknock-01f system for said power means, a moving actuator and a detentmovable to and from a position to be engaged by said moving actuator,and when so engaged, being further movable for causing said knock-01fmeans to stop the loom, a circuit having two branches and a current feedline to said branches, an electro-magnet in one said branch forretaining said detent out of contact with said moving actuator, a stopmotion detecting means in the other said branch effective upon failureof a weaving thread to initiate stopping of the loom, and means in saidfeed line for passing current to said electro-magnet and for reducingsparking and slowing the action of the stop motion detecting means whichcomprises an incandescent lamp having a low resistance when its filamentis relatively cool and a relatively high thermal lag and means forming apart of said knock-off means for resetting said detent as the loom isstarted.

5. In a loom the combination of an electrically operated power means, aknock-off system for said power means, a moving actuator and a detentpivoted to an arm so mounted that when the detent is moved into the pathof the moving actuator, it will be swung against a part of the saidknock-0E means thereby to cause it to stop the loom, a circuit havingtwo branches and a current feed line to said branches, and means forminga part of said branch circuits and feed line for signalling the stoppingof the loom upon power failure to the loom or upon failure of a weavingthread, which includes a magnet in one branch for holding the detent outof the path of the moving actuator, a thread fault detector in the otherbranch operable to complete a circuit through said branch upon failureof a weaving thread and a resistance in said feed line, said resistancehaving a value such that it passes a low current to said magnet withoutbecoming heated to a point to increase its resistance substantially andfurther having a substantial thermal lag so that when current isincreased upon shorting the said thread fault detector to ground, thevoltage drop at the magnet will be appreciably retarded.

6. In a loom the combination of an electrically operated power means, aknock-off system for said power means, a moving actuator and a detentpivoted to an arm so mounted that when the detent is moved into the pathof the moving actuator, it will be swung against a part of the saidknock-ofi means thereby to cause it to stop the loom, a circuit havingtwo branches and a current feed line to said branches, and means forminga part of said branch circuits and feed line for signalling the stoppingof the loom upon power failure to the loom or upon failure of a weavingthread, which includes a magnet in one branch for holding the detent outof the path of the moving actuator, a thread fault detector in the otherbranch operable to complete a circuit through said branch upon failureof a weaving thread and a resistance in said feed line, said resistancecomprising an incandescent lamp having a low resistance when itsfilament is relatively cool and a relatively high thermal lag.

7. In a loom the combination of an electrically operated power means, aknock-off system for said power means, a moving actuator and a detentmovable to and from a position to be engaged by said moving actuator,and when so engaged, being further movable for causing said knock-offmeans to stop the loom, a circuit having two branches and a current feedline to said branches, one said branch comprising a closed circuithaving a detent holding magnet therein, the other said branch havingtherein a stop motion detector normally in open circuit, the resistancein said first branch being appreciably greater than that of the secondso that when the circuit in the second branch is completed, current isdiverted from the first to the second, and a low resistance of highthermal lag in said feed line to retard the change occurring upon suchdiversion of current.

8. In a loom the combination of an electrically operated power means, aknock-off system for said power means,

a moving actuator and a detent movable to and from a position to beengaged by said moving actuator, and when so engaged, being furthermovable for causing said knockoff means to stop the loom, a circuithaving two branches and a current feed line to said branches, one saidbranch comprising a closed circuit having a detent holding magnettherein, the other said branch having therein a stop motion detectornormally in open circuit, the resistance in said first branch beingappreciably greater than that of the second so that when the circuit inthe second branch is completed, current is diverted from the first tothe second, and a low resistance of high thermal lag in said feed lineto retard the change occurring upon such diversion of current and meansincluding a spring clip movable with said knock-oft means for engagementwith said detent for resetting it upon starting the loom.

9. In a loom stop motion circuit the combination of a source of directcurrent, branches one of which comprises a closed circuit and another ofwhich is normally maintained open, an electro-magnet in said closedcircuit and a thread fault detecting means in said open circuit, a feedline from said source of current and a resistance in said line andhaving a relatively high thermal lag.

10. In a loom stop motion circuit the combination of a source of directcurrent, branches one of which comprises a closed circuit and another ofwhich is normally maintained open, an electro-magnet in said closedcircuit and a thread fault detecting means in said open circuit, a feedline from said source of current and a resistance in said line whichcomprises an incandescent lamp of low resistance when cool and having ahigh thermal lag.

References Cited in the file of this patent UNITED STATES PATENTS

